Radial engine



A. G. LARSON.

RADIAL ENGINE.

APPLICATION FILED NOV-. 4.1919. 1,394,419. Patented Oct. 18, 1921..

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WITNESS. Z [IV/Z2170]? A. G. LARSON.

RADIAL ENGINE. APPLICATION FILED NOV:4.1919.

' Patented 0011. 18, 1921.

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ARVEID (51-. lhrli'dlfiihl, 0F GRINNELL, Hill/57A, ASSIGNUR T0 DCiDG-E TOOL COMPANY, @1 5 GRINNELL, IUW'A, A 00E PQRATION.

HLAJJEAL EN Lndi ladllbt 7'0 all whom it may concern:

it known that l, Anvin G. LAnsoN, a citizen of the United States, and a resident of Grinnell, in the county of Poweshiek and State of .llowa, have invented a certain new and useful Radial Engine, of which the following is a specification,

T he object of my invention is to provide in an internal combustion engineof the type in which a plurality of cylinders are an ranged radially in a series around a central rotating crank, a structure in which each cylinder has one movable valve, and in which all the cylinders are supplied with fuel from a common manifold, fuel being supplied through a port at the side of the cylinder.

A further object is to provide such a structure designed particularly for use with aeroplanes and the like of the air cooled type in which the parts are so arranged that during part of the intake stroke of the piston cool air may be drawn through the single movable valve for cooling the valve and the piston and the cylinder.

A further object is to provide in such a type of engine a means for supplying the fuel to the cylinders properly mixed with air and vaporized.

With these and other objects in View my invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawin s, in which: a

igure 1 shows a side elevation of an engine embodying my invention, many of the parts being omitted, the view being intended to show the general arrangement of the cylinders around the crank shaft.

Fig. 2 shows a vertical, central, sectional view through the crank case and the lower cylinder.

Fig. 3 shows a sectional view through one of the cylinders taken on the line of the intake port; and

Fig. 4 shows a manifold.

In building engines for aeroplane service a number of important problems have been involved. One of these has been that of cooling the engine.

I have provided an air cooled engine havdiagrammatic View of the Specification of Letters Patent.

Patented (Get. 11%, Serial No. 335,757.

ing a single movable valve arranged to serve as an exhaust valve, and also as a means for admitting cool air, which serves to cool the valve and piston and cylinder, as well as supplying auxiliary air to the fuel mixture.

1 have adopted the type of engine having the cylinders arranged around the common crank shaft, and have employed a rotating crank shaft with fixed cylinder.

In an engine of the type herein shown in which the crank shaft is rotatable and the cylinders are fixed, there is involved the problem of getting the fuel mixture properly vaporized and mixer with air to the cylinders.

It is impossible to follow the system employed in the engine where the cylinders rotate around the crank shaft, because in that type of engine the fuel is supplied through the crank shaft to the crank case and from the crank case to the cylinder. That system of fuel supply is impracticable in the ty e ofengine herein considered on account of the rotating crank shaft.

have found it not desirable, in an air cooled engine, to feed the fuel through the outer end of the cylinder by means of the ordinary puppet valve structure for the fol lowing reason: In an air cooled engine where fuel is fed through the engine cylinder and the fuel feed is controlled by a puppet valve or the like, it is of course necessary to provide a manifold or conducting chamber lead ing to the valve opening. As a result of this structure the cylinder top has a wall which is prevented from contact with the air by the manifold or conducting. chamber. in such a structure the parts are likely to warp and also cause preignition by remaining so hot as to ignite the gases when under a slight compression.

- I have, therefore, adopted the plan of supplying fuel Which will be hereinafter more fully described.

11 the accompanying drawings I have shown a'crank shaft indicated by the reference numeral 10 having the crank 11 within the crank case 12.

Arranged around the crank is a series of internal combustion engine cylinders 13 of the air cooled type having the radial fins 14.

he cylinders 13.are suitably mounted in openings in the crank case and roject beyond the crank case as at 15. lllounted in vention I have shown seven each cylinder 13 is a piston 16 suitably connected with the crank shaft 11 by means of a connecting rod 17.

In the drawings accompanying my application, which illustrate a form of my inlinders.

In the head or outer end 0 each cylinder is a valve seat 18. Arranged to coact with the seat 18 is a valve 19 having a stem 20 extending outwardly through a suitable guide 21 and making contact with a rocking lever 22.

, On the stem 20 is a spring 23 for yieldingly holding the valve in closed position.

On the shaft 10 is a sleeve 23 carrying a cam 24. The sleeve 23 is operated by any one of a number of conventional two-to-one gear devices common to gas engines, and rotated at one-half the speed of the engine shaft. Slidably engaging the cam 24 is a reciprocating valve operating rod 25 which is connected by a ball joint 26 with the link 27 The link 27 is pivoted to the rocking lever 22. l

Suitably supported on the side of, the crank case 12 is an annular tubular manifold 28 designed to be connected with an ordinary carbureter.

In the wall of each cylinder 13 spaced from the outer end thereof a suitable distance is a series of inlet ports 29. Connected with the manifold near each 0 linder is a fuel conducting chamber 30 which flares circumferentially of the cylinder so as to carryvfuel to all of the inlet ports 29 of that cylinder. The conducting chamber 30 is so mounted by bolts 30 that a slight movement will be permitted between the said conductor 30 and the manifold 28, to permit expansionv of the cylinders without cracking the manifold. This conductor also permits quick and easy assemblage betweenthe bolts and the said manifold to overcome any variation which might be due to inaccuracies of construction.

I will now describe the practical operation of my engine.

It may be mentioned that the cylinders are fired in sequence and are their outer ends with the ordinary spark plugs 31, which are connected with the ordinary timing mechanism and source of electrical energy.

I will describe the operation in connection with one of the cylinders. i

It may be mentioned in this connection also that my device is particularly designed for'use in engines of the four cycle type.

Assuming that the piston 16, as shown in Fig. 2, has just made the scavenging or ex haust stroke, it will be understood that the cam 24 is of such shape that in the rotation of the shaft 10 the cam holds the valve 19 open during a considerable part of the intake stroke.

that the mixture may cylinder.

rovided at the In fact the valve is held open until h piston is almost in a position to clear intake ports.

The advantage of this structure will be explained hereafter.

ust beforethe iston' clears the intake ports, the cam reac es a point in its movement where it permits the spring 23 to close the valve 19. y

The tension of the spring 23 is su'tficient to hold the valve closed during the remaining part of the movement of the piston away from the head of the cylinder.

.During such latter part of such movement a partial vacuum is created in the cylinder, and when the piston clears the intake ports, a charge of fuel mixture is drawn into the cylinder. v

It may be mentioned in this connection be one which has been vaporized and mixed with air in any suitable standard carbureter.

During the compression stroke, 19, of course, remains closed.

When the piston 16 reaches the head of the cylinder, the charge is fired and on the ex-- plosion strokethe cam 24 is of such shape that the valve 19 opens when the piston is approaching its limit of movement away from the valve, and when the crank is, with relation to the cylinder under consideration, approximately forty-five degrees from dead center.

The explosion stroke is then completed and the scavenging occurs. After the scavenging stroke another intake stroke takes place. During this intake, on account of the fact that the valve is open and during part of the piston movement, cold air is drawn in from the outside, which cools the head of the The valve and the valve seat and piston also furnish a supply of auxiliary air for the fuel mixture.

By this arrangement of the single movable valve in the head of the cylinder whereby the cylinder head can be cooled, I have provided a four cycle engine with a single movable valve, which can be made much larger than any of the ordinary engines ofthis type I know of, on account of the extra cooling accomplished in the manner hereinbefore set forth.-

No fuel mixture will escape into the crank case for the reason that at all times there is some cylinder drawing the fuel from the manifold with suction, so that the pressure in the manifold is always less than the pressure in the crank case.

The advantages of a structure such as herein disclosed will be largely obvious from the foregoing description.

It will be seen that I have provided an engine of the type having the cylinders arranged around a common crank shaft, the cylinders being fixed and the crank shaft rotatable, so that the engine can be made larger and more horse power secured than with the ordinary rotary type.

Attention is called to .the extreme simplicity of the method of feeding the fuel from a single intake manifold to the side of the cylinder in such a way that the fuel may be properly vaporized and mixed with air before being supplied to the cylinder. and to the advantage of the single valve serving both for exhaust purposes and for the intake of auxiliary air, whereby I am enabled to cool the head of the cylinder better than can be done with any cylinder which has an intake puppet valve arranged in the head of the cylinder.

Attention is also called to the extreme simplicity of parts whereby an engine of maximum horse power may be secured with parts of minimum weight and size.

I believe I have been able to secure all the advantages of the rotary type of engine and have avoided the disadvantages of such a type of engine to which attention has been called hercinbefore.

Some changes may be made in the construction and arrangement of the various parts of my improved engine without departing from the essential features and purposes thereof, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope. Iclaim as my invention:

' 1. In a device of the class described; a shaft having a crank thereon; a crank case for. said crank; a series of cylinders arranged radially around the crank and secured to said crank case; pistons in said cylinders; connecting rods connecting said pistons with said crank; a valve seat in the head of each cylinder; a valve on the interior of the cylinder for coacting with said seat, having a stem projecting from the head of the cylinder; means for yieldingly holding the valve seated; means for operating said valve from a cam shaft, each cylinder having an intake port in its side; an annular fuel manifold adjacent to said crank case; and conducting chambers for connecting the manifold with the intake ports of the respective cylinders, the said conducting members being so mounted that expansion of the cylinders may be permitted without cracking the manifold.

2. An internal combustion engine having a crank case and radially arranged cylinders, each of which is provided with an intake port, an annular intake manifold of a diameter substantially equal to the diameter of said crank case, a detachable chamber for each of said intake ports and in communication with said manifold, so mounted that a slight expansion and contraction of the cylinders may be permitted without injury to the manifold.

3. An internal combustion engine having a crank case and radially arranged cylinders, each of which is provided with an intake port, an annular intake manifold. a detachable chamber for each of said intake ports and in communication with said manifold so mounted that a slight expansion and contraction of the cylinders may be permitted without injury to the manifold.

Des Moines, Iowa, October 20, 1919.

. ARVID'G. LARSON. 

